There are two issues here. One is rebooting and the other is shutdown.
To reboot you can use the DEVCON (Device Console) command to reboot your system. I think the command should look something like:
I don't currently have a 2000 system running to test this on but if the syntax is incorrect, you shoud be able to find the correct syntax by typing:
The second issue is shutting down.
Windows NT 4 and Windows 2000 do not come with a built-in command line shut down command. The NT4 and windows 2000 Resource Kits from Microsoft contain a command line shutdown program. I have a copy. If you will PM me and let me know how to get it to you, I would be happy to send it to you.
Now that I think about it, I think that this utility allows you to shutdown and to also reboot by using a -R switch.
I hope that this helps.